1. Field of the Invention
The present invention relates generally to the fields of molecular biology and medicine. More particularly, it concerns MUC18-targeting peptides.
2. Description of the Related Art
Studies addressing the role of the immune system in tumor growth and metastasis have yielded conflicting and often counterintuitive results. Over the 1970's, Prehn and colleagues proposed that the immune response mediated by lymphoid cells could paradoxically lead to tumor cell stimulation (Prehn, 1971; Prehn, 1982; Wexler et al., 1976). To date, the interplay of immunity, inflammation, and cancer is still not entirely understood (Coussens and Serb, 2002; de Visser et al., 2005). To add a further level of complexity—depending on the experimental model used—it is evident that host immunity can actually lead to enhancement, suppression, or even no effect at all on the metastatic potential of tumor cells, so that no global generalizations can be easily made (Fidler, 1997).
Specifically in the B16 mouse melanoma model, previous reports demonstrate that melanoma cells can be stimulated by lymphocytes (Bartholomaeus et al., 1974) and that melanoma progression can indeed be delayed if tumor-bearing mice are rendered immunosuppressed (Fidler and Gersten, 1980). However, the basis for these intriguing experimental observations remains elusive. In particular, the relevance of cell subpopulations from the more primitive layers of the immune system such as B-1 lymphocytes (Berland and Wortis, 2002; Hardy and Hayakawa, 1986; Kantor and Herzenberg, 1993; Fagarasan et al., 2000) on tumor phenotype has not been fully elucidated, although it has been suggested that B-1 cells can physically interact with melanoma cells (Perez et al., 2008).
Although B-1 lymphocytes may contribute to the metastasis of melanoma cells, it is not clear how to therapeutically inhibit this interaction to decrease metastasis of a cancer. Part of the reason that methods for decreasing this interaction are, to the knowledge of the inventors, essentially non-existent is due to the fact that the mechanism by which these cells interact has not previously been elucidated. Clearly, there exists a need for new methods and therapeutics for the treatment of cancer.